Drug delivery devices in the form of infusers are known in the prior art for administering medicament to a patient. Infusers are intended for mounting onto a patient's skin for self-administration of a medicament. Activation of the infuser not only provides for injection of a needle into a patient's skin, but also to cause auto-drive of a plunger to drive medicament into the patient via the injected needle. Typical infuser constructions have the needle fixed to the reservoir. For example, with reference to U.S. Pat. No. No. 5,858,001 to Tsals et al., an infuser is disclosed which is activated through swivel displacement of a reservoir-containing body. A needle is attached to the Tsals et al. device which is also caused to penetrate the skin of a patient with the swivel displacement of the body. The needle is fixed to the body so as to move therewith. Other types of infusers are known, including those which use standard needle-mounted syringe barrels. With infusers, the ability to independently control the injection of the needle, from the administration of medicament, is limited.